Conventional Lithium-ion (Li-ion) multi-cell batteries require a battery management system to prevent over-charge, under-charge and other difficulties and to balance cells to eliminate state-of-charge mismatches. As the number of voltage of a multi-cell and the number of cells increase, the potential for mismatch in conventional multi-cell batteries also increases since, in a series configuration, some of the cells can be charged to a higher voltage than others. There is a need for multi-cell battery designs that ameliorate the requirement to monitor and control the balancing during charging and the charging.
In Lithium ion cells, electrode materials tend to swell or contract due to the insertion or ejection of the Lithium ions into and out of the intercalation spaces during charging and discharging. As the cells are repeatedly charged and discharged, the electrode structure can weaken and thereby reducing adhesion to the current collector. The reduction in adhesion can reduce battery life. There is also a need for multi-cell battery designs that ameliorate the effects of repeated charging and discharging.
Injection molding provides a relatively inexpensive method of manufacturing. However, many of the materials used in injection molding are permeable to water vapor and organic solvent vapors. The transfer of moisture into a lithium-ion battery and electrolyte vapor out of a lithium-ion battery can affect the performance and the life of the battery. There is also a need for multi-cell battery designs that substantially incorporate a moisture barrier.
Due to chemical compatibility and corrosion problems, the connectors that are attached to the anode (−) or cathode (+) electrodes in a lithium ion battery are limited to a few metal types. In a multi-cell battery, there is a need for connector designs for connecting a positive electrode to a negative electrode.
Embodiments of Lithium ion (Li-ion) multi-cell batteries are disclosed. In the embodiments disclosed herein below, the requirements for individual monitoring and controlling charging of each cell and for monitoring and controlling charge balancing are ameliorated. In one or more of the embodiments disclosed, the effects of repeated charging and discharging are ameliorated. In one or more embodiments, the multi-cell battery includes configuration materials that substantially provide a moisture barrier.
In one or embodiments, the multi-cell battery of these teachings includes a container having a number of cell cavities, a number of electrochemical assemblies, each electrochemical assembly enfolded, one of the enfolded electrochemical assemblies disposed in each one of the cavities, each one of the electrochemical assemblies having a positive electrode and a negative electrode and a separator material between the positive electrode and the negative electrode. The multi-cell battery of this embodiment also includes an electrolyte in each of the cell cavities, the electrolyte comprising a lithium salt and a redox shuttle, the electrolyte and electrodes selected to, during battery operation, provide substantially a predetermined voltage across each electrochemical assembly in each cell cavity, the redox shuttle being selected to substantially provide shuttle operations when voltage across each electrochemical assembly in each cell cavity reaches substantially another predetermined voltage, and a cover disposed on the container, the cover being permanently attached to the container so as to form a substantially hermetic seal between the cover and the container, the cover forming a seal between each of the cell cavities.
Other embodiments of the multi-cell battery of these teachings are also disclosed.
For a better understanding of the present teachings, together with other and further objects thereof, reference is made to the accompanying drawings and detailed description and its scope will be pointed out in the appended claims.